Refactor the packet scheduling out of ClientView. Add intelligent

resending, timeouts, packet discarding. Add notification event for
packet discarding. Add priority scheduling for packet queues.
Add outgoing duplicate detection facility. Correct packet sequencing.
Make provisions for automatic server side throttle adjustments (comes
in next installment)

OpenSim/Region/ClientStack/LindenUDP/LLQueItem.cs

@@ -25,6 +25,7 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+using System;
 using libsecondlife.Packets;
 using OpenSim.Framework;
 
@@ -39,5 +40,6 @@ namespace OpenSim.Region.ClientStack.LindenUDP
         public Packet Packet;
         public bool Incoming;
         public ThrottleOutPacketType throttleType;
+        public Object Identifier;
     }
-}
+}